1. Technical Field
This invention relates to vacuum cleaning devices and, more particularly, to an improved separator for use in conjunction with liquid bath type vacuum cleaners.
2. Discussion
Vacuum cleaners of various designs are used in residential and commercial settings for cleaning purposes. These appliances develop suction to create airflow which picks up large and small dust particulates from a surface being cleaned. These particulates are then separated from the air within the vacuum cleaner for later disposal.
One type of vacuum cleaner is a canister type which has a relatively stationary canister which is connected to a movable wand by a flexible connecting hose. One particular design of the canister type vacuum cleaners is known as a liquid bath type. This type of vacuum cleaner directs incoming air and particulates into contact with a liquid bath which is typically water, which in turn absorbs particulate matter. Liquid bath type cleaners in general have a significant advantage in that their filtration mechanism uses readily available water, thereby eliminating the need for replaceable filters. In addition, these machines provide a room humidifying effect since some of the water in the liquid bath becomes dissolved in the air discharged from the vacuum cleaner during use.
Numerous designs of liquid bath type vacuum cleaners are presently known. The following U.S. Patents, the disclosures of which are hereby to the assignee of the present invention, relate to various improvements in liquid bath type vacuum cleaner: U.S. Pat. Nos. 2,102,353; 2,221,572, 2,886,127; and 2,945,553.
Although devices constructed in accordance with the above mentioned issued patents perform satisfactorily, designers are constantly seeking to reduce the amount of fine dust and dirt particulates that escape entrapment in the liquid bath type filter and which are expelled by the vacuum cleaner back into the ambient environment. In this regard, designers have been striving to improve the operation of a part of such vacuum cleaners which is generally known as the separator. Up until the present, the separator of a vacuum cleaner has functioned to provide a first stage of filtration by impeding the flow of medium and large size dust and dirt particles, which have not been trapped in the liquid bath, through the vacuum cleaner and back into the ambient environment.
The efficacy of the separator could be further enhanced, however, if the separator was operable to provide a second stage of filtration to remove the fine dust and dirt particulates which enter it, and which would otherwise normally be exhausted into the ambient environment. One method of accomplishing this would be by employing a method of separation known generally as centrifugation. Briefly, centrifugation involves the application of centrifugal force to an air mass entrained with liquid or solid particulate matter. The centrifugal force is typically produced by drawing the contaminated air mass into an annular chamber and spinning the chamber and contaminated air mass therein radially at a high angular velocity. The magnitude of centrifugal force created, which may be on the order of 10,000 Gs or more depending on the angular velocity of the chamber, forces the liquid and the contaminants, i.e., dust and dirt particulates, radially outward toward the outer wall of the chamber where they are exhausted through openings in the chamber wall, thereby leaving a clean air mass within the rotating chamber. If applied to a separator of a vacuum cleaner, centrifugation could be used to help filter out the smaller dust and dirt particulates which would otherwise pass through the vacuum cleaner and back into the ambient environment.
To still further enhance the filtering of small dust and dirt particles which have escaped being trapped in the liquid bath filter and which have entered the separator, it has been found that if microscopic liquid particulates, or droplets, from the liquid bath are also drawn into the separator and allowed to coalesce with the dust and dirt particulates entrained in the intake air, a marked improvement will occur in the amount of dust and dirt particulates removed by the separator. It has further been found that this improvement can be achieved with negligible adverse effects on other aspects of the vacuum system, such as the suction-like air flow through the system.
In view of the foregoing, it is a principal object of the present invention to provide an improved separator for a vacuum cleaner for more effectively separating fine dust and dirt particulates entrained in intake air from the intake air.
It is a further object of the present invention to provide an improved separator operable to centrifuge small dust and dirt particulate matter from intake air before the intake air is expelled back into the ambient environment.
It is still a further object of the present invention to provide an improved separator operable to allow liquid particulates to be drawn therein and coalesce with fine dust and dirt particulates entrained in intake air.
It is yet another object of the present invention to provide an improved separator operable to remove coalescing liquid, dust and dirt particulates from within the separator, thereby producing a clean air mass which may be expelled back into the ambient environment.
It is still another object of the present invention to provide an improved separator capable of removing coalescing liquid, dust and dirt particulates entrained in intaked air, which produces only negligible adverse effects on the suction-like force of, and airflow through, a vacuum system.